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Allowance for Loan and Lease Losses and Reserve for Unfunded Commitments - Summary of TDR's by Loan Category (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Financing Receivable Modifications [Line Items]
Number of Loans	10	5	6
Pre-Modification Outstanding Recorded Investment	$ 3,117	$ 1,154	$ 2,741
Post-Modification Outstanding Recorded Investment	2,630	$ 1,154	$ 2,741
Charge-offs	487
Specific Reserves	$ 357
Commercial Real Estate
Financing Receivable Modifications [Line Items]
Number of Loans	5	2	2
Pre-Modification Outstanding Recorded Investment	$ 1,655	$ 898	$ 979
Post-Modification Outstanding Recorded Investment	1,655	$ 898	$ 979
Specific Reserves	$ 111
Commercial and Industrial
Financing Receivable Modifications [Line Items]
Number of Loans	3
Pre-Modification Outstanding Recorded Investment	$ 1,246
Post-Modification Outstanding Recorded Investment	759
Charge-offs	487
Specific Reserves	$ 246
Residential Real Estate
Financing Receivable Modifications [Line Items]
Number of Loans	2	3	4
Pre-Modification Outstanding Recorded Investment	$ 216	$ 256	$ 1,762
Post-Modification Outstanding Recorded Investment	$ 216	$ 256	$ 1,762

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-Publisher FASB
-Name Accounting Standards Codification
-Topic 310
-SubTopic 10
-Section 50
-Paragraph 33
-URI http://asc.fasb.org/extlink&oid=84173941&loc=SL6953676-111524

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-Topic 310
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-Section 50
-Paragraph 33
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